WO2007107150A1

WO2007107150A1 - Joint device

Info

Publication number: WO2007107150A1
Application number: PCT/DE2007/000499
Authority: WO
Inventors: Roland Auberger
Original assignee: Otto Bock Healthcare Ip Gmbh & Co. Kg
Priority date: 2006-03-17
Filing date: 2007-03-15
Publication date: 2007-09-27
Also published as: JP4819914B2; JP2009529927A; CN101404959B; DE502007001802D1; TW200800125A; DE102006012716B3; US7935153B2; EP1996128A1; CN101404959A; ATE446063T1; EP1996128B1; US20090076618A1; TWI317633B; RU2406467C2; RU2008139211A

Abstract

The invention relates to a joint device for orthoses or prostheses, with an upper part (2), with a lower part (3) mounted on the upper part (2) in such a way as to turn about a pivot axis, and with a braking means that brakes or blocks a pivoting movement of the lower part relative to the upper part, wherein a helical spring (5) is arranged between two run-on surfaces (6, 7) and is mounted such that it can be braced about a rotation axis parallel to the pivot axis and comes into contact with the run-on surfaces when braced in their direction.

Description

joint device

The invention relates to a joint device for orthoses or prostheses with an upper part and a rotatable about a pivot axis mounted thereon lower part and a braking device that decelerates or blocks a pivotal movement of the lower part relative to the upper part.

From the prior art, a plurality of joint devices for orthoses and prostheses are known, which allow a pivotable mounting of two prosthesis or orthosis components against each other. In an arrangement of the joint device, for example, as a knee joint, it is desirable to be able to set a damping in the swing phase and in the stance phase.

An assembly of a hinge device in a uniaxial shoulder joint should allow locking of an arm prosthesis or orthosis against falling. The same applies to the arrangement of the joint device in an elbow joint.

To set up the braking device in these joints different principles of action are possible, in addition to a positive locking in predetermined locking positions there is the possibility of a hydraulic damping or deceleration of the movements. However, such hydraulic controls are technologically very expensive and are disadvantageous in terms of space and weight.

Object of the present invention is to develop a joint device that can be opened or closed with a low switching force and at the same time requires a very small amount of space. In particular, the medial-lateral extent should be kept as low as possible to allow for use in an orthosis inconspicuous wearing under clothing. According to the invention this object is achieved by a hinge device with the features of claim 1. Advantageous embodiments and further developments of the invention are listed in the subclaims.

The joint device according to the invention for orthoses or prostheses with an upper part and a lower part rotatably mounted about a pivot axis and a braking device which decelerates or blocks a pivotal movement of the lower part relative to the upper part, provides that a spiral spring is arranged between two contact surfaces and around one Twist axis is mounted braced parallel to the pivot axis in the direction of the contact surfaces, wherein at a tension in the direction of the contact surfaces, the coil spring comes into contact with these. As a result, the side edges of the coil spring are pressed against the contact surfaces. This allows the construction of a very high braking torque at very low switching forces and switching paths by friction. Due to the design as a coil spring, it is possible to allow a very small size in medial-lateral extent, even if a relatively large diameter must be taken into account. Due to the tensioning of the spiral spring in the direction of the contact surfaces, the individual spiral paths attempt to move in the direction of the contact surfaces. However, due to the contact surfaces, this is not possible, so that the spiral wedged and a braking or locking torque can be realized. Due to the wedge effect, the tension is increased, so that there is a self-reinforcing system. If a relative movement of the upper and lower part is carried out against the Windungsrichtung, the spiral paths tend away from the contact surfaces, so that an almost unhindered movement is always possible, unless the friction due to the bias is not so large that the opening movement is at least compensated.

A development of the invention provides that the contact surfaces are formed contoured, in particular radially conical or radially curved to the

To increase friction surface and their radially outwardly one behind the other

Spiral gears of the spiral spring to make usable. This will be a progressive Braking behavior achieved. The coil spring is preferably contoured corresponding to the contact surfaces in order to provide the largest possible friction surface between the contact surfaces and the spiral spring edges. A conical or constant curved configuration of the contact surfaces and the spiral spring contour allows an additional wedge effect, which causes a high power gain. Also contemplated are discontinuous cross-sectional geometries, eg multiple conical or curved contours, similar to that of a fir tree. As a result, the width can be reduced at a given wedge angle.

A particularly compact construction is made possible when the axis of rotation of the spiral spring coincides with the pivot axis of the joint.

In a conical configuration of the contact surfaces, an angle between 10 ° and 50 ° is preferred. Smaller angles harbor the risk of self-locking, larger angles increase the installation space in the medial-lateral direction and reduce self-reinforcement, which is not desirable.

The coil spring is preferably adjustable in tension and can be in its rest position in contact with the contact surfaces. This ensures that in the pivoting direction to be locked, due to the self-initiating and reinforcing braking effect always a safe braking effect is ensured, even if a certain moment must be applied to move the joint device, against this direction, to the initial To overcome the braking effect of the coil spring.

A development of the invention provides that the spiral spring is coupled to an actuator, which tensions or relaxes the spiral spring. This makes it possible to carry out an active control of the articulation device, for example, by an always free mobility is given by a voluntary relaxation of the coil spring, ie an expansion or contraction of the coil spring away from the contact surfaces. On the other hand, by a sufficiently large tension in the direction of the contact surfaces a permanent and safe Locking of the hinge device or braking the Verschwenkbewe- supply done.

The actuator is preferably a servo or servomotor, which can be coupled to reinforce the actuating force and the tension of the coil spring in the direction of the contact surfaces or away therefrom with a lever, which in turn acts on the coil spring. In a home position, the lever may be spring loaded in the latching direction to perform wear compensation. This is easy to realize in particular by a tension spring. In order to ensure a safe deceleration or locking in case of failure of the actuator, so to provide a fail-safe joint device, the coil spring is biased against the actuator in the locking direction. If the actuator fails, the coil spring automatically turns in the direction of the contact surfaces, resulting in an initial braking effect, which is reinforced by the self-reinforcement and thus the tension of the coil spring against the contact surfaces. This makes it possible to always lock a pivoting direction in case of failure of the actuator. In the case of a knee joint or a knee joint orthosis, the flexion would be blocked in order to prevent unintentional buckling.

A development of the invention provides that a sensor device is provided which measures moments, angular positions of the upper and lower parts to one another or forces acting on the joint device. This sensor device is coupled to a control unit that activates the actuator in dependence on the measured variables or parameters and braces or relaxes the spiral spring relative to the contact surfaces. As a result, depending on the load and depending on the position, a blockage or release of the braking device is effected, as a result of which a situation-adapted braking of the joint device takes place. For example, when a prosthesis carrier or orthosis carrier tripping, the braking device can be activated and the joint device can be locked so that unintentional buckling is prevented. The knee flexion can thus be selectively limited. A development of the invention provides that the actuator is coupled to a control unit, which causes an activation or deactivation of the actuator via myoelectric signals. This allows joints to be locked or unlocked in a certain position due to myoelectric signals.

It is also possible that a device for detecting the spatial orientation of the upper part and / or the lower part is coupled to the actuator. Also, a device for detecting the occurring accelerations of the upper part and / or the lower part or the devices attached thereto may be coupled to the actuator. This makes it possible that the orthosis / prosthesis or the device in which the joint device is used, by means of a Absoultwinkelsignals, ie an orientation of either the upper part or the lower part to the Lot, can be controlled. By the position of the upper part and the lower part to each other, the joint angle, for example, the knee angle is known, so that the absolute orientation in space from both the upper part and the lower part and the attached thereto devices is known. The device can therefore be equipped as an absolute angle sensor on the upper part or the lower part or on a device attached thereto. This makes it possible to carry out the actuation of the actuator on the basis of information about the spatial orientation of the joint device or of the system in which the joint device is arranged. It is also possible to carry out this control on the basis of the occurring and measured accelerations. Thus, depending on the absolute angle and the accelerations that occur, the brake can be activated or disengaged.

In a mehrgängigen embodiment of the coil spring a particularly easy adjustability is guaranteed. A concomitant loss of friction surface can be compensated by an increase in diameter of the coil spring and contact surfaces. Non-linear spiral geometry makes it possible to achieve progressive braking behavior. It is also possible to vary the operating torque over the number of spiral turns. The more turns a spiral spring has, the longer is the actuation travel, however, the braking torque can be adjusted very well. In order to realize a certain adjustment tolerance and activation softness, a contact surface can be mounted limited axially displaceable. The spiral geometry is not limited to continuously curved free spaces or spiral paths. Spiral gears with changing cross sections, inclines, orientations or the like can also be provided. Block-like elements can also be provided.

An exemplary embodiment of the invention will be explained in more detail below with reference to the figures. Show it:

Figure 1 - a hinge device in an assembled state;

Figure 2 - a bottom view of a hinge device according to Figure 1;

Figure 3 - a plan view of a partially cut joint device;

Figure 4 - a sectional view through a fully assembled joint device;

FIG. 5 shows an enlarged detailed representation of the detail A of FIG. 4

Figure 6 - various views of a multi-start ^Euler's spiral spring;

Figure 7 - various views of a nonlinear coil spring; such as

Figure 8 - a variant of the hinge device in partial view.

FIG. 1 shows a plan view of a fully assembled joint device 1 with a top part 2 and a bottom part 3. The designation upper part and lower part does not represent a technical limitation to a specific arrangement; instead, a top part can be arranged both at the proximal and distal end of a prosthesis or orthosis be, the same applies accordingly for the lower part.

The upper part 2 has an L-shaped bracket 21 which is axially slidably connected to the upper part 2, screwed or placed. About screws 71 is a contact surface, which is not shown in this figure, bolted to the bracket 21. In front of the bracket 21, an actuating lever 40 protrudes in the direction of the lower part 3 and can by an actuator, not shown in FIG be pivoted about a pivot axis 4 both directions. The lever 40 is pivotally mounted relative to the upper part 2 and moves a coil spring which is non-rotatably attached to the lower part 3 via screws 51 on the lower part 3. The upper part 2 and the lower part 3 can be fastened to fastening elements of orthoses or prostheses.

2 shows a bottom view of the hinge device 1 is shown. The upper part 2 forms a support surface on which the second contact surface is rotatably mounted via screws 61 and connected to a functional unit. The lower part 3 is pivotable relative to the upper part 2 about a central pivot axis 4. On the lower part 3, a circular head piece is formed, on which the spiral spring is fixed via the screws 51.

A possible embodiment of the coil spring 5 is shown in the figure 3, which shows a sectional view through the upper part 2, the lower part 3 and the coil spring 5. The bracket 21, the lever 40 and the upper circular lid 53 are not shown.

The spiral spring 5 is rotatably mounted on the lower part 3 via the screws 51 distributed around the circumference. It has a circular cross section with a catchy spiral passage which extends from the outside to the rotation axis 4, counterclockwise, spirally inwards. Parallel to the pivot axis 4 and coinciding therewith, the coil spring 5 can be tensioned in the winding direction by an actuation of the lever 40 in the counterclockwise direction so that the spiral spring 5 contracts inwards in the direction of the axis of rotation 4. The individual spiral paths migrate inwards and then lie against the contact surfaces 6, 7, which are mounted non-rotatably on the screws 2, 61, 71 on the upper part 2. Depending on the design of the contact surfaces 6, 7 and the coil spring 5, it is possible to achieve braking in a rotation in or against the Windungsrichtung. On the basis of Figure 4, the structural design and the operation of the hinge device 1 can be particularly well recognized. In the sectional view of Figure 4, the upper part 2 and the lower part 3 are mutually pivotally mounted about the pivot axis 4 displaceable together. On the upper part 2 with the bracket 21 fastened by screws or bolts, contact surfaces 6, 7 are rotatably mounted via the screws 61, 71. The contact surfaces 6, 7 have a conical contour and are arranged relative to one another such that an expanding wedge space forms radially outward. Within this wedge space, the coil spring 5 is arranged, which is non-rotatably fixed by the distributed at its periphery screws 51 on the lower part 3. The coil spring 5 is on the one hand directly on the lower part 3 and on the other hand on the lid 53. The lever 40 is also pivotable about the axis of rotation 4, which is also the Verspannachse stored and acts on the center of the coil spring 5. If the lever 40, as shown in the Figure 1, operated counterclockwise gersinn, the coil spring tightens 5 inside. The individual spiral gears with their conical contour try to move inwards. However, this is not possible because of the lateral limitations by the contact surfaces 6, 7, which act as brake discs. The lateral surfaces of the coil spring 5 wedged against the stop surfaces 6, 7, whereby a braking or a locking torque is realized. If, however, the lever is moved counterclockwise in the direction of the winding, the spiral length widens outward. As a result, the friction between the lateral spiral surfaces and the contact surfaces 6, 7 is reduced or eliminated, so that in extreme cases there is no longer any contact between the coil spring 5 and the contact surfaces 6, 7. The joint or the joint direction 1 can thus be moved freely. If an actually locked joint or a locked joint device 1 is moved counter to the winding direction of the coil spring 5, the friction between the side surfaces of the coil spring 5 and the contact surfaces 6, 7 causes a widening of the spiral gears, so that the joint is always free in this direction moves while automatically locking in an opposite direction of movement. In the illustrated principle, the Normakraft necessary to build up the braking or locking torque acts perpendicular to the respective wedge surface. In order to reduce the stresses on the components, such as coil spring 5 and contact surfaces 6, 7 at a predetermined braking torque, it is recommended possible to realize many friction surfaces. In the present case, two contact surfaces 6, 7 are provided. These contact surfaces 6, 7 are pushed apart when locking the hinge device 1 and thus rub against the spring fifth

If the two abutment surfaces 6, 7 are supported in a limited axially displaceable manner, then the radially inwardly directed movement of the spiral gears additionally causes friction of the outer friction surfaces 36, 537 of the abutment surfaces 6, 7 on the lower part 3 and the circular cover 53 arise a total of four braking surfaces, which means a relief for the spring 5 at a given, to be realized braking torque. The number of friction surfaces can be further increased by connecting the contact surfaces 6, 7, or the lower part 3 and the cover 53 with a lamination stack, as shown in FIG. It is also possible to store several contact surfaces and coil springs axially next to each other. If one looks at two spiral springs with different winding direction, the joint can be locked in both directions of movement at the same time.

About the lever 40, as already stated, the coil spring 5 can be braced or relaxed, whereby the joint or the hinge device 1 is either opened or locked. As a lever 40 may also serve a gear or a gear segment. Via a gear transmission can then take place an immediate coupling of a servomotor as an actuator to the gear and about with the coil spring or the coil springs, whereby the required space can be reduced. An adaptation to changing force relationships can take place via a change in the lever length over a change in the transmission lever instead of a change in the lever length. In the partial view of Figure 5, a radial sliding bearing 8 is further provided between the upper part 2, 21 and the lower part 3, which bears against end faces of the contact surfaces 6, 7 and the upper part 2 and the bracket 21. The radial bearing 8 does not have to rest on the end faces, it is important that it is secured against excessive axial displacements. As a result, when the spiral spring 5 is not tensioned, it is possible to slide about the pivot axis 4. FIG. 5 likewise shows an angle sensor 9, which senses the angular position of the upper part 2 relative to the lower part 3 and transmits this data to a control device, which in turn actuates an actuator (not shown), for example an actuator or servomotor. As a result, the joint device 1 can be locked or opened. In addition, a torque sensor may be integrated in the structure in the upper part 2 or preferably in the lower part 3.

Instead of the screws 51, the lid 53 can be screwed directly to the lower part 3 via a thread, with an anti-rotation lock being provided. As with the screws 51, the gap can be adjusted via the thread and the parts held together.

In order to avoid unwanted tension, it may be necessary that the upper part 2 and the attached bracket 21 allow axial play, so that the two braking or contact surfaces 6, 7 are axially displaced easily to each other. Then it is envisaged that the bracket 21 is fixed with play on the upper part 2 or via two bolts which allow axial displacement, are interconnected.

The geometry of the spiral curve of the coil spring 5 has a strong influence on the characteristics of the joint device 1. Spirals with many turns have a longer actuation path than spirals with few turns, however, the realized braking torque can be set much finer. Non-linear spiral geometries are possible, for example, to achieve a progressive braking behavior or to optimize the load of the coil spring. In order to reduce the actuation torque via the lever 40, a plurality of turns can be cut parallel to one another, ie a multi-turn spiral passage can be formed, as shown for example in FIG.

When used in knee joint orthoses or prostheses, it is provided that the joint device 1 is set in a locking mode, which guarantees that the joint is not freely pivotable in the event of a failure of the actuator. This can be achieved by a bias of the actuating lever 40, for example via a spring, in a locked position. The opening of the hinge device or the braking device then takes place actively against a spring force, for example, against a bias on the coil spring 5. Alternatively to a bias on the coil spring 5, a separate spring can be provided which simultaneously causes automatic wear compensation. The opening of the hinge device 1 is then actively against the spring force. If the bias voltage is selected against the actuator in the middle of the torque range of interest, the braking torque to be realized can be further strengthened or weakened.

It is also possible to provide a larger number of contact surfaces 6, 7, for example, stacked one behind the other, as in a multi-plate clutch, to further reduce the load on the coil spring 5. It is also possible, instead of a straight conical design of the contact surfaces 6, 7, to provide a curvature in order to allow a particular increase in the braking torque in the case of a displacement of the spiral gears inwards.

Are the contact surfaces 6, 7 formed so that they form a radially outwardly tapering wedge space, the directions of rotation are reversed accordingly, as by a widening of the coil spring 5, the application to the stop surfaces 6, 7 causes and the braking torque can be realized. With the illustrated embodiment, an opening of the joint device under load by a motor actuator or even by a manual operation is easily possible. In an emergency and in case of failure of an actuator, the hinge device is always locked in a pivoting direction when in the initial position, the coil spring 5 is in contact with the contact surfaces 6, 7. By pivoting the upper and lower parts 2, 3 to each other then carried out a realization of a braking torque and an increase in the braking effect by wedging.

As an alternative to the embodiment shown with only one spiral spring 5, two spiral springs can be arranged axially adjacent to one another in the opposite direction, so that a brake which is effective in both pivoting directions can be obtained, which requires few components and can be switched under load in both directions of movement.

The above-described joint device can also be used with any number of spinning components and is therefore also suitable for overrunning clutches or backstops.

FIG. 6 shows a plan view of a spiral spring 5 with Euler spiral turns, that is to say a linear spiral geometry. A total of four spiral paths are provided, each with three and a half turns, so that due to the relatively large surface of the spiral gears results in a relatively easy adjustment and rotatability of the coil spring 5. In the figure 6a, in which a section along the line AA in Figure 6 is shown, the arrangement of the coil spring 5 between two contact surfaces 6, 7 can be seen. Holes 55 are formed on the outer circumference of the spiral spring 5, in the present case symmetrically opposite one another, through which the fastening screws or bolts 51 can be guided in order to fix the spiral spring to the lower part 3. In the figure 6a, the wedge angle α of the coil spring 5 is located, which is between 10 ° and 50 °, in this case at about 30 °. The wedge angle α is at the same time the wedge angle which is formed between the contact surfaces 6, 7. If the spiral spring tapers in the radial direction, instead of recognizing, as can be seen in FIGS. 6a and 6c, a funnel-shaped configuration towards the axis of rotation 4, the wedge angle α is oriented the other way around.

FIG. 6b shows the enlarged partial representation of region B from FIG. 6a.

FIG. 7 shows a spiral spring 5 in plan view with a non-linear spiral geometry. The spiral spring 5 has four spiral gears with a winding length of approximately 225 °, resulting in a much stiffer spring characteristic than in the coil spring 5 of Figure 6 results. Also in the coil spring 5 according to Figure 7 bores 55 are distributed on the circumference of the coil spring 5, present in a larger number than in the coil spring of Figure 6. Smaller holes 56 are used to save material, but can also be used together with bolts for torque transmission , In the figure 7a, the wedge angle α or the wedge angle of the not shown contact surfaces 6, 7 to each other to recognize. FIG. 7 c shows the cup-like depression facing the axis of rotation 4.

FIG. 8 shows, in a partial sectional view, similar to that of FIG. 5, an alternative embodiment of the articulation device. Instead of a transmission of the frictional forces exclusively at the contact surfaces of the spiral spring 5 at the contact surfaces 6, 7 and the outer friction surfaces 36, 537, in the lower part 3 and the cover 53 splines 30, 530 are incorporated, in which Reibla- mellen 531, 532, 533, 31, 32, 33 are axially displaceable and rotatably inserted. Instead of the spline 30 and bolts or other positive connection elements can be provided. The rotationally fixed bearing can be produced by a positive connection of projections on the circumference of the lamellae 31, 32, 33, 531, 532, 533 and grooves and notches in the lower part 3 and cover 53. Between the disk sets 31, 32, 33, 531, 532, 533 are on the upper part 2 associated side of the hinge means bolts 16, 17 for torque transmission in the contact surfaces 6, 7 and the bracket 21 and arranged the upper part 2. On these bolts 16, 17 friction plates 71, 72, 62, 63 are attached, whereby an axially displaceable, torque-rigid connection is formed. The bolts 16, 17 are pressed into the contact surfaces 6, 7. Now, if the coil spring 5 is rotated in the winding direction, put the spiral spring gears to the contact surfaces 6, 7 and press them outward. As a result, the disk packs are pressed together due to the axial mobility and the torque-rigid mounting in the lower part 3 and on the upper part 2, not shown, and prevent or complicate a rotational movement of the upper part 2 relative to the lower part 3. A final friction pair is by the area between a the upper part 2 associated output member 73, 64 and the lid 53 and the lower part 3 realized.

In the illustrated embodiment, a total of 16 friction surface pairings are provided, whereby the friction surface can be substantially increased. The more fins are provided, the larger the friction surface. Even with an embodiment of the hinge device with the lamellae, an arrangement of several coil springs, possibly in opposite Windungsausrichtung possible. Likewise, applications are possible with spinning components.

Claims

claims

1. joint device for orthoses or prostheses, with an upper part and about a pivot axis rotatably mounted thereon lower part, and a braking device which decelerates or blocks a pivotal movement of the lower part relative to the upper part, characterized in that a spiral spring (5) between two contact surfaces (6, 7) is arranged, which is mounted braced around a rotation axis (4) parallel to the pivot axis and in tension in the direction of the Anlaufflächen (6, 7) comes into contact with them.

2. Joint device according to claim 1, characterized in that the axis of rotation (4) coincides with the pivot axis.

3. joint device according to claim 2, characterized in that the contact surface (6, 7) is formed radially conically or radially curved.

4. joint device according to claim 3, characterized in that the spiral spring (5) corresponding to the contour of the contact surfaces (6,

7) is contoured.

5. Joint device according to one of claims 3 or 4, characterized in that the cone angle (α) of the contact surfaces (6, 7) between see 10 ° and 50 °.

6. Joint device according to one of the preceding claims, characterized in that the spiral spring (5) is adjustable in its tension.

7. Joint device according to one of the preceding claims, characterized in that the spiral spring (5) in its initial position in contact with the contact surfaces (6, 7).

8. Joint device according to one of the preceding claims, characterized in that the spiral spring (5) is coupled to an actuator which braces the coil spring (5) in or against the winding direction of the spiral on the contact surfaces (6, 7).

9. joint device according to claim 8, characterized in that the actuator is a servomotor.

10. Joint device according to claim 8 or 9, characterized in that the actuator via a lever (40) or a gear or toothed wheel part with the coil spring (5) is coupled.

11. Joint device according to claim 10, characterized in that the lever (40) or the gear is spring-loaded in the locking direction.

12. Joint device according to one of claims 8 to 11, characterized in that the spiral spring (5) is biased in its initial position against the actuator in the locking direction.

13. joint device according to one of claims 8 to 12, characterized in that a sensor device (9) is provided which measures forces, moments and / or angular position of the upper and lower parts (2, 3) to each other and is coupled to a control unit, which activates the actuator in dependence on the measured variables and braces the spiral spring (5).

14. Joint device according to one of claims 8 to 13, characterized in that the actuator is driven by myoelectric signals.

15. Joint device according to one of claims 8 to 14, characterized in that a device for detecting the spatial orientation of the upper part and / or the lower part is coupled to the actuator.

16. Joint device according to one of claims 8 to 15, characterized in that a device for detecting the occurring in the orthosis accelerations of the upper part and / or the lower part or attached thereto devices is coupled to the actuator.

17. Joint device according to one of the preceding claims, characterized in that the at least one contact surface (6, 7) is mounted axially displaceable.

18. Joint device according to one of the preceding claims, character- ized in that the spiral spring (5) is designed to be more continuous.

19. Joint device according to one of the preceding claims, characterized in that the spiral spring (5) has a non-linear spiral geometry.

20. Joint device according to one of the preceding claims, characterized in that the contact surfaces (6, 7) are coupled with a lamellar dressing in order to increase the number of friction surfaces.